Waterproof felted materials presently exist for a variety of product applications. For instance, it is common for boat decks to have waterproof felted surfaces on their external decks which allow for traction of crew members' shoes while providing watertight surfaces. This material is useful to boat owners since it provides a surface which can be cleaned easily, maintains a dry boat interior, and which improves traction. Shortcomings with present-day felted boat decks are their lack of longevity and inability to conform to curved shapes.
Another example of waterproof felted materials currently in use is that of putting surfaces of miniature golf courses. This surface, or artificial grass, simulates the feel and resistance of grass on a golf course, and yet provides a waterproof surface for low maintenance and continuous player use. A shortcoming with these artificial grass surfaces is that they often separate or peel from underlying concrete substrates over the course of time. Also, they too cannot be applied to contoured shapes as unitary strips of material. For example, a putting surface straddled by two upright short walls would require three independent strips of felted material where total coverage of the surface and walls is desired. If a continuous strip of felted material is used, the felted material would lift up from the corners over time.
Various other materials have been made which provide waterproof barriers having sufficient structural integrity to withstand weathering and continuous use. These materials have typically been used to line construction surfaces such as roadways and rooftops, and the surfaces of recreational vehicle compartments such as boat decks and sports utility vehicle trunks. However, these materials often experience structural failure due to the aging of adhesive used to bind the layers. This adhesive often disintegrates over time causing a layer of a multilayered barrier to separate from an underlying substrate. Additionally, the manufacture of many of these materials requires costly production steps, which are, in many instances, labor intensive and time consuming. For instance, much of the prior art teaches rolling and pressure techniques to apply layers to a substrate. Such techniques require a large space to accommodate rollers and often several workers to operate such machinery. Examples of such structures are manufactured by the Westlake Plastic Company of the United States, the Agru Company of Belgium, the Simona Company of Germany and the Gunnie Sanyo Company of Japan. These companies manufacture fabric backed materials consisting of a woven fabric or fabric blend such as cotton, polyester or fiberglass, which is pressed into a polymeric sheet backing. Such "fabric backed" materials, often fray. In some instances the fabric can peel from their backings completely.
Waterproof barriers have been devised with multiple layers using adhesive to bind them together into an integral structure. For example, U.S. Pat. No. 4,319,854 describes a moisture control method and means for pavements and bridge deck constructions comprising layers of glass fiber mesh embedded in layers of asphalt. This moisture control method is not readily adapted for use as a moisture barrier in a recreational vehicle. U.S. Pat. No. 4,464,215 describes a process of applying a unitary construction barrier by applying to a preformed barrier structure an adhesive bituminous sheet material.
U.S. Pat. No. 4,787,780 describes a method of waterproofing with a self-sealing bentonite sheet material composite article. The method includes a layer of a flexible sheet material adhered to a layer of a composition comprising a non-hydrated water-swellable clay intimately contacted with a polypropylene, polybutene or mixtures thereof. The clay mixture is sufficiently tacky to adhere to the flexible sheet. While this method creates a waterproof barrier, it does not provide for the permanent addition of a second solidifying coating material. Neither is the connection between the clay mixture and the underlying sheet permanent.
Furthermore, the manufacture of multilayered adhesive bonded barriers often exposes workers to volatile organic compounds which are released during application of the adhesives.
Accordingly, it is seen that a need remains for a waterproof felted material which can be molded and permanently bonded to an underlying substrate. Additionally, a need remains for a waterproof felted material which can be used as a permanent substrate for a solidifying coating. A need further remains for a waterproof felted material which is not dependent on adhesive or pressure in order to maintain the bond between layers. It is to the provision of such therefore that the present invention is primarily directed.